Structural tubing.



W. WILLS.

STRUCTURAL TUBING. APPLLCATION FILED MAR. 20. 1911.

Patented Sept. 28, 1915.

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arm-rag P-m i ora ion.

.WAYNE WILLS, OF CHICAGO,. ILLINOIS, QASSIGNOR BY MESNE ASSIGNMENTS, T0

- AMERICAN SEATING COMPANY, 'A CORPO'R ATION.

To all whom it may concern Be it known that I, WAYNE WILLS, a citizen of the United States, residing at Chicage, in the county of Cook and Sta'teof Illinois, have invented certain new and useful Improvements in Structural Tubing, of which the following is a specification.

The object of my invention is to provide metallic tubing of steel, or metal having properties similar to steel, and possessing characteristics that adapt it for many purposes for which cast metal, rolled bars of flat.or angular section, and other materials, are now used.

Vhile cast iron, or other cast metal, lends itself readily to the production of irregular forms, it does not possess the degree of strength desirable for many purposes. Rolled bars of flat or angular s'ection,'while well adapted to many. uses, do not for some purposes possess the rigidity of a tubular construction and where a finishedand pleas ing appearance is desirable are inferior to tubular forms. The high cost of seamless tubing restricts its use to a comparatively narrow field. Tubing of the cross sections heretofore available, formed of a-strip of metalwelded or otherwise secured together at its edges, possesses disadvantages in both the matter of initial cost and the cost and.

difficulty of bending or otherwise forming the tubular material. Tubing formed from a strip of metal, the edge portions of which abut against each other without being secured together, which I shall in this application designate as open tubing, can be produced at a lower cost than seamless or welded tubing, but open tubing. of the usual shape or cross section heretofore available cannot be economically bent cold to any considerable extent without a marked change in section or buckling.

The object of my invention more particularly stated is the production of a type of tubing that can be readily bent either during the operation of forming the tubing from a strip of metal or after the manufacture of the tubing has been completed.

In the drawingFigure 1 represents a straight section of a preferred form of tubing embodying my invention. Fig. 2 is a transverse section of the tubing shown in Fig. 1; and Fig. 3 shows a piece of the tub ing reversely bent and illustrating the man- Specification of Letters Patent. 7

scrcaucrnnar. TUBING.

v Patenteti ept. 2S, 1915.

Application filed M2 rch 20,1911. Serial No. 615,775.

ner in which it may be curved in the construction of articles for which it is adapted.

I have discovered that tubing approximately triangular in cross section can be bent'coldwithout a marked change in section or buckling, and without the necessity of using means within the tubing to prevent such change of section orbuckling. Triangular section tubing may be bent as described, regardless of whether the meeting edge portions of the strip of material of which the tube is formed are welded together or merely abut against each other.-

referred to by rolling the same from a strip 1 of metal.

I do not in this application, however, lay claim to any particular method of manufacturing the tubing, but claim as my invention the triangular section tubing independently of the method by which it is made, and shall not therefore in this application enter upon any description of the process of forming the tubing.

Specifically themethodof forming tubing of the section herein described and the method of bending the same may take many different forms, and in this application, therefore, I claim the method or process generically and without reference to the particular instrumentalities, whether the same be rolls, dies, or other suitable mechanism.

Referring to the drawing, it will be observed that the preferred embodiment of my invention consists of a strip of metal rolled or otherwise formed into a tube approximately triangular in cross section, the edge portions of the strip being brought together to form one of the angular edges of the tube I and there turned outward to form a longitudinal projecting flange. The walls of the tube diverge in substantially V -form in cross-section from the flange and from the extremities of the divergent portions the walls converge in a direction away from the flange toward the part opposite the flange. The approximately triangular form shown in the drawings with the side opposite the flange convex is one embodiment of the shape described, although, of course, strict adherence to the specific form illustrated is infer necessary provided the shape conforms to the foregoingdescription. The edge portions 1 of the strip of metal contact with each other, as illustrated in the draw- 7 ing, and mav or may not be welded or other wise secured together.

The initial tension between the edge portions of the'strip of metal-of which the tube is formed may be brought about during the manufacture of the tubing in a variety of ways. Thesides of the tubing which con verge toward the meeting edges 1 may at one stage'of the formation of the tube-be given an outwardly curved or convex form, 'andlater the convexity may be rolled out of these side portions, thus causing theedge portions l to move in converging planes toward the junctions between the two edges.

. Such convergingmovement of the side walls of the tubing would set up the'tension or pressure referred to between the meetlng edge portions of the material.

The tubing above-described, of approxi mat'ely triangular cross section, can be bent cold, and without the use of means within the tubing to prevent change of section 0r buckling, provided the bending be'effected ma plane passing through one of the anthe other two angular edges.

In the drawing I illustrate tubing of approximately triangular cross section having the edge portions, 1, of the metal meet at one of the angular edges of the tubing and being there turned outwardly in the form of a longitudinal flange. The plane in whlch the tubing is bent is represented in Figs. 1

and 3 by the dotted line rectangles A, and, as illustrated in Fig. 3, the tubing may be so bent in the. plane A either toward or from the angular edge thereof at which the edge portions of the strip of metal meet. Tubing 'of this type is preferably so disposed in the structure in'which it is used that the principal stresses act in the plane of the longitu dinal flange formed by the meeting edges,

1, -1. of the strip of metal. The flange thus adds greatly to the strength of the structure,

gular edges of the tube and midway between while the tubular part contributes'largely to its rigidity and to its resistance to stresses in other directions. I

While I have illustrated and described a preferred form of triangular flanged tubing,

my invention is not confined to the precise cross sectional form illustrated or to the preci'se form or manner of forming the longitudinal flange at the meeting edge portions of the strip of-metal, and therefore itwill be understood that in the following claims I do as'necessarily limited to the precisestructure shown 1n the drawings. As above'ex- 'plained, I use the term open tube as descriptive of a tube formed from a strip of metal, the edge portions of which meet and abut against each other but are not necessarily secured together by welding or other" 3 not use the words triangular and flange and the extremities of the divergent-parts merging by-curves into a flattened curved j wall located opposite said flange whereby the tube may be readily bent into curved" j 2. A metal tube consisting of a .strip of metal bent into the form' of an open tube with the edge portions of the strip meeting 85,, and projecting ina flange and with the walls of the tube diverging in substantially V- form in cross section from the flange and the extremities of the divergent partsmergr ing by curves into a flattened curved wall located opposite said flange, said tube being curved in a plane passing through said flange and substantially bisecting the cross section of the tube.

In testimony whereof, I have subscribed my name.

IVAYNE WILLS. Witnesses: v

V. L. VILLS,

C. B. STILLWELL. 

